There's some notion running around that folks aren't voting their economic interests or that they are being somehow irrational when they vote Republican. I don't know if I agree with this. I mean, it may be correct, on average, but not necessarily evidence that they are being in any way irrational. Maybe middle-class families are simply making a "high" guess at their chances of moving upward in the income distribution (becoming rich). If we think of the market economy as partly based purely on hard work, partly on ability, and partly on luck, then at least part of the outcome is based on a sort of lottery, and there's plenty of anecdotal evidence that suggests that many people overestimate their chances in a lottery. Perhaps middle class voters who support McCain's tax structure are (often wrongly) estimating that they will be one of the few who move upward into the $250,000+ income range, the top 5%.